Self-coupling pump unit

ABSTRACT

An immersible pump unit comprising a liquidtight motor and a pump with a lateral connection and guiding means which, on lowering of the pump unit, guides the pump connection to the vicinity of a coupling unit, the pump unit being suspended so that the central axis of the pump runs slightly obliquely downwards, there being close to the coupling unit a support for the pump unit in its lowered position. There is in the extension of the coupling unit beyond the support, at least one stop with an inclined plane facing the coupling unit, the point of contact between the pump unit and the inclined plane of the stop lying a distance below an imaginary line of operation for the force of reaction generated at the connection and coupling unit by the pump pressure.

I United States Patent [151 3,659,964 Dahlgren 1 May 2, 1972 54]SELF-COUPLING PUMP UNIT 3,427,982 2/1969 Englesson ..4i7/360 x [72]inventor: Jens Karl Adolf Dahlgren, Stockholm, primary R b -n M w lk Sed n Attorney-Sughrue, Rothwell, Mion, Zinn and Macpeak [73] AssigneezStenberg-Flygt AB, Solna, Sweden 57] ABSTRACT [22] Filed: 1970 Animmersible pump unit comprising a liquidtight motor and a [21] APPL67,329 pump with a lateral connection and guiding means which, onlowering of the pump unit, guides the pump connection to the vicinity ofa coupling unit, the pump unit being suspended so [30] ForeignApplication Priority Data that the central axis of the pump runsslightly obliquely downwards, there being close to the coupling unit asupport 1969 Sweden "12019/69 for the pump unit in its lowered position.There is in the extension of the coupling unit beyond the support, atleast one stop [52] U.S. Cl ..4l7/360, 222/385 with an inclined planefacing the coupling unit the point of [5 Int. ontact between the pumpunit and the inclined plane f the Field Of Search 2/ 80, 385; 417/360,361; stop lying a distance below an imaginary line of operation for415/201 the force of reaction generated at the connection and couplingunit by the pump pressure. [56] References Cited 7 Claims, 2 DrawingFigures UNITED STATES PATENTS 3,234,885 2/1966 Englesson ..4l7/360 XSELF-COUPLING PUMP UNIT BACKGROUND OF THE INVENTION 1. Field of theInvention The invention relates to a pump unit immersible in a liquidand consisting of a liquidtight-enclosed motor and a pump withconnection leading from the pump housing, the pump unit having a guidewhich, on lowering and raising of the pump unit, guides the pumpconnection to and from the vicinity of a coupling unit, the pump unithaving a suspension device preferentially so placed that the centralaxis of the pump unit runs slightly obliquely downwards when the pumpunit is freely suspended therein.

2. Description of the Prior Art In pump units intended for operationwholly or partially immersed in the pumped medium, there is greatinconvenience in maintenance work if the pump units are permanentlyinstalled. To eliminate these inconveniences it is a known practice toarrange for the pump units to be lowered into the pumped medium, guidedalong guides and, in their lowered position, bearing against a couplingunit on an outlet pipe for the pumped medium. The connection of the pumpunit must in this position close tightly against the outlet pipe withoutneeding to be attached to it by means, for example, of screws.

These known devices admittedly enable the pump unit to be relativelyeasily raised out of the pumped medium for maintenance work or the like.But certain inconveniences remain, for example the difficulty of gettingthe connection of the pump unit to close tightly against the couplingunit of the outlet pipe after the pump unit has been lowered and duringits operation.

The US. Pat. No. 3,018,925 describes a device of this kind, in which theflanges which connect a pump unit to an outlet pipe form an angle with avertical plane. The advantage of this is that the pump unit, in itsimmersed position in the pumped medium, seals against the connectingpipe under the influence of the gravity of at least part of the pumpunit. This provides a relatively good seal between pump and outlet pipe.

Other devices of this kind are known in which the slidepieces which runalong the guides are articulated to the pump unit, which, afterimmersion in the pumped medium, is turned slightly round an essentiallyhorizontal axis, the pump unit being thereby lowered in the direction ofthe connecting flange of the outlet pipe. In such devices as well theweight of the pump unit is used to achieve a seal with the couplingflange, in that a certain torque arises around the axis around which theslide-shoes are rotatably arranged. In these devices as well the sealbetween the pump unit connection and the coupling flange is obtainedonly through the torque produced by the weight of the pump unit.

Another known procedure is to furnish the pump unit with grippingdevices which grip across the flange of the outlet pipe. The grippingdevices and/or flange of the outlet pipe are given suitably charnferedshoulder areas so that a wedge efi'ect arises between the grippingdevice and the flange. In this way a fairly good seal is obtainedbetween the pump unit and coupling unit when the area of the outlet islimited to relatively small diameters and/or the pump pressure to suchlow values that the torque occasioned by the outlet area, the pumppressure and the leverage does not overcome the torque determined by theweight of the pump unit and the distance to its point of gravity.

Such devices are, however, no longer of advantage for pumps with largeforces of reaction since they lifl the pump unit off the flange of theoutlet pipe and leakage occurs.

SUMMARY OF THE INVENTION The aim of the present invention is to overcomesuch disadvantages and to find a new solution which is applicable bothto small and large pumps, especially the latter, and provides asufficiently high sealing pressure between the pump unit and couplingunit, where the pressure cannot be overcome but is instead magnified byforces of reaction arising during pumpmg.

III

The invention thus relates to a pump unit immersible in a liquid andconsisting of a liquidtight-enclosed motor and a pump with connectionleading laterally out of the pump housing, the pump unit having a guidewhich, on lowering and raising of the pump unit, guides the pumpconnection to and from the vicinity of a coupling unit, the pump unithaving a suspension device preferentially so placed that the centralaxis of the pump unit runs slightly obliquely downwards when the pumpunit is freely suspended therein. The invention is essentiallycharacterized in that a support for the pump unit in its loweredposition is arranged at or close to the coupling unit, in addition towhich, in the extension of the coupling unit beyond the support, thereis arranged at least one possibly laterally displaced stop with aninclined plane facing the coupling unit, the point of contact betweenthe pump unit and the inclined plane being arranged to lie below theforce of reaction at the pump connection and coupling unit resultingfrom the pump pressure and the area.

The connection of the pump housing and/or the coupling unit may suitablyhave special bearing and sealing surfaces. According to a specialembodiment of the invention these bearing and sealing surfaces may be ofessentially spherical form, whereby they become self-centring and allowtolerances in the relations between the positions 6' the coupling unitand the stop.

The suspension device should preferentially be attached to the upperside of the enclosed motor on the central axis of the pump unit or onthe side thereof furthest from the connection. According to a preferredembodiment of the invention the pump unit bears against the inclinedplane via at least one pin, stud, roller or the like. This pin, stud,roller or the like may be arranged so as, on raising and lowering of thepump unit, to engage with the guiding device for guiding of the pumpunit to and from the connection.

Further advantages are gained through a special embodiment of theinvention, in which coupling unit, support, stop and inclined plane arecombined in one unit which, for example, can be placed on the bottom ofa basin, cesspool or the like.

BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention willnow be described without limiting the invention thereto with referenceto the attached drawings:

FIG. 1 shows the invention in schematic form, viewed from the side andpartially in cross-section, the pump unit being shown with continuouslines in raised position and with broken lines in lowered position.

FIG. 2 shows a partial cross-sectional side view of a modification ofthe present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The pump unit is in theconventional manner immersibly made up of a liquidtight-enclosedelectric motor and a pump, preferentially a centrifugal pump. Laterallythere projects from the pump housing a stub 3 with a connection 4, theend surfaces of which run essentially vertically. Pump and motor arecoaxially arranged and, on the upper side of the motor on the commoncentral axis 1, there is a suspension device in the form of an eyelet 2.The eyelet 2 need not lie on the central axis I even if the subsequentdescription assumes this position. The point of gravity of the pumphousing here lies, inter alia because of the connecting stub 3projecting laterally from the pump housing, at the side of the centralaxis 1, to the left of it in the figure, so that the point of gravity Tpof the entire pump unit will lie outside the central axis 1.Consequently, during suspension of the pump unit, i.e. when its point ofgravity Tp is below the suspension eyelet 2, the central axis 1 will runslightly obliquely downwards. Owing to the eccentric position of thepoint of gravity Tp the pump unit, and thus also the connection 4 of thepump housing, hangs slightly obliquely, as shown by continuous lines inthe figure. Should the point of gravity Tp coincide with the centralaxis 1 of the pump unit.

the suspension device can be placed, for example, further to the rightin the figure so that, when suspended, the pump unit hangs slightlyobliquely, with the side facing the coupling unit 5 slightly lower.

The pump unit is intended to be coupled to the coupling unit 5, to theflange 6 of which the pumping pipe is intended to be connected. Thecoupling unit 5 has an essentially vertical connecting body having abeating and sealing surface 7, which fits the corresponding bearing andsealing surface 8 of the connection 4 of the pump housing. In theembodiment under consideration these bearing and sealing surfaces 7, 8are spherical, so that the pump housing can be rotated around themidpoint of the sphere without the seal being affected thereby, and sothat the connection 4 of the pump housing becomes self-centring in thecoupling unit 5.

When the pump unit, slightly obliquely suspended in the eyelet 2, islowered, being guided in the known manner with some clearance on one ormore essentially vertical U-shaped guides 10, the unit will finallyassume a position with the connection 4 of the pump housing roughlyopposite the coupling unit 5. A support 9 prevents the connection 4 ofthe pump housing. from being lowered past the coupling unit 5 andfurthermore, according to the invention, has the following function.

At the moment when, on lowering of the pump unit on the first occasion,the connection 4 of the pump housing comes into contact with the support9, the pump unit still hangs obliquely. The lower part of the connection4 of the pump housing is then at a slightly greater distance from thecoupling unit 5 than its upper part. On being further lowered the pumpunit, at the connection 4 of the pump housing, will be carried by thesupport 9, whereas it is not supported at the opposite side of the pumphousing, i.e. on its right side in the drawing, as a result of which thepump unit is rotated in the figure clockwise around a horizontal axisand the bearing and sealing surface 8 of the pump housing thusapproaches the bearing and sealing surface 7 of the coupling unit 5. Atthe end of the downward movement a pin, stud, roller 11 or the likecomes up against a stop 12 connected to the coupling unit 5 through abase plate 15. This takes place on an inclined plane 13 of the stop 12facing the coupling unit 5. The point of contact 14 between the stud orthe like 11 and the inclined plane 13 here lies the distance below thenow preferentially horizontal midplane of the pump housing andconnecting stud 3, and therefore below the force of reaction R resultingfrom the pump pressure, whereby, through the resulting wedge effect, thebearing and sealing surfaces 7 and 8 are pressed together. The placingof the point of contact 14 according to the invention, viewed in thedirection of the force of reaction, below the point of engagement of theforce of reaction, has the following advantageous effect.

When the pump is working especially at a large head, i.e. pump pressure,and large area of engagement there is generated through the forces ofreaction owing to the said pump pressure and area a large resultingforce R in the midplane, directed to the right in the figure. Owing tothe distance a of this force R from the point of contact 14, a clockwisetorque is obtained in the figure, which presses the stud 11 furtherdownward towards the inclined plane 13, with consequent intensificationof the force which presses together the bearing and sealing surfaces 7,8.

The greater the force R, the greater accordingly is the intensificationof thecompressing force.

By making the inclination of the plane 13 steeper, a further increase ofthe force pressing together the bearing and sealing surfaces 7, 8 can beattained. The downward directed suction aperture also contributes to anincrease of the sealing force during operation of the pump.

The stop 12 with the inclined plane 13, the support 9 and the couplingunit 5 with coupling flange 6 are, in the embodiment described,connected together by means of a base plate 15, which can suitably beplaced on the bottom of a basin, cesspool or the like, and from whichthe guides 10 may also proceed.

By using two studs 11 or the like, a three-point mounting is obtained,as a result of which the pump unit stands very rigid and neverthelesscan be easily raised without manual release of any engaging device.

In pump units of this kind the invention thus provides an arrangementwhich is self-centring and self-coupling, provides an increasing sealingpressure with rising pump pressure and is usable for very large andheavy pump units.

In FIG. 2 a variation of the pump mounting flange is provided. The stop11 is still located below the central thrust R so that a clockwisetorque is produced, however, the bearing and sealing surface which ispressed together, will be at a point 18 adjacent support 9'.

What 1 claim is:

l. A pump unit immersible in a liquid and consisting of aliquidtight-enclosed motor and pump for pumping liquid into an outputconduit comprising:

a housing;

a connection member extending laterally out of the pump housing andterminating in a flange with a lower support portion;

a base member having a camming stop member;

at least one corresponding stop member positioned on the housing, and

a coupling member having a lower support member for supporting theflange support portion, the coupling member positioned at such adistance relative to the camming stop member that any reaction forcegenerated during the pumping action along the axial length of theconnection member will be above the contact point of the housing stopand base member stop thereby creating a torque force about the contactpoint that increases the sealing contact force between the connectionmember flange and coupling member in direct relation to the torqueforce.

2. A pump unit as in claim 1, where the lower support portion of theconnection member flange is a protruding stud member.

3. A pump unit as in claim 1, where the coupling member is integral withthe base member.

4. A pump unit as in claim 1, where the sealing surface of theconnection member flange and the coupling member is spherical.

5. A pump unit as in claim 1, further including a suspension deviceadapted to connect the housing to a cable or the like, the suspensiondevice positioned on the housing so that the connection member isinclined downward while suspended.

6. A pump unit as in claim 2, where the lower support member ispositioned beneath and outward of the coupling member opening.

7. A pump unit as in claim 6, where the spherical connection memberflange is adapted to surround the coupling member sealing surface.

I i i l i

1. A pump unit immersible in a liquid and consisting of aliquidtight-enclosed motor and pump for pumping liquid into an outputconduit comprising: a housing; a connection member extending laterallyout of the pump housing and terminating in a flange with a lower supportportion; a base member having a camming stop member; at least onecorresponding stop member positioned on the housing, and a couplingmember having a lower support member for supporting the flange supportportion, the coupling member positioned at such a distance relative tothe camming stop member that any reaction force generated during thepumping action along the axial length of the connection member will beabove the contact point of the housing stop and base member stop therebycreating a torque force about the contact point that increases thesealing contact force between the connection member flange and couplingmember in direct relation to the torque force.
 2. A pump unit as inclaim 1, where the lower support portion of the connection member flangeis a protruding stud member.
 3. A pump unit as in claim 1, where thecoupling member is integral with the base member.
 4. A pump unit as inclaim 1, where the sealing surface of the connection member flange andthe coupling member is spherical.
 5. A pump unit as in claim 1, furtherincluding a suspension device adapted to connect the housing to a cableor the like, the suspension device positioned on the housing so that theconnection member is inclined downward while suspended.
 6. A pump unitas in claim 2, where the lower support member is positioned beneath andoutward of the Coupling member opening.
 7. A pump unit as in claim 6,where the spherical connection member flange is adapted to surround thecoupling member sealing surface.